Question: Which is the opera the lyrics of which were by Philip Glass?
Paraphrase: Philip Glass wrote the lyrics for what opera?
SPARQL (Wikidata):  select distinct ?sbj where { ?sbj wdt:P676 wd:Q189729 . ?sbj wdt:P31 wd:Q1344 } 
Answer: Akhnaten, Satyagraha, La Belle et la Bête, Les Enfants terribles, Orphée